EP 0669309 B1 19971105 - Process for the preparation of tetrachloro-1,4-benzoquinone
Title (en)
Process for the preparation of tetrachloro-1,4-benzoquinone
Title (de)
Verfahren zur Herstellung von Tetrachlor-1,4-benzochinon
Title (fr)
Procédé pour la préparation de la tétrachloro-1,4-benzoquinone
Publication
Application
Priority
DE 4405929 A 19940224
Abstract (en)
[origin: DE4405929C1] The invention relates to a process for the preparation of tetrachloro-1,4-benzoquinone in high purity by reacting chlorine and concentrated hydrochloric acid with hydroquinone, by a process in which some of the hydroquinone to be employed is introduced into 4 to 6 times the molar amount - based on the total amount of hydroquinone - of 20 to 37 % aqueous hydrochloric acid which contains catalytic amounts of iron(III) ions and an anionic dispersant, passing 1.5 to 2.0 times the molar amount - based on total hydroquinone - of chlorine gas into this solution at a temperature of 20 to 90 DEG C, subsequently adding the remainder of the hydroquinone as a solid or in dissolved form, passing in 1.5 to 2.0 times the molar amount of chlorine gas, during which process the hydrochloric acid concentration is first kept at 25 to 31 % by adding water, raising the temperature to 100 to 107 DEG C while passing in more chlorine gas (1.3 to 1.9 times the molar amount) and while diluting with water down to a hydrochloric acid concentration of 20 to 22 %, adding, after the passing-in of chlorine gas has ended, a higher-boiling organic solvent which is not miscible with hydrochloric acid in an amount of 0.15 to 1.0 part based on 1 part of tetrachloro-1,4-benzoquinone, or in an amount of approximately 1 - 10 % by weight, based on the reaction mixture, and subsequently subjecting the reaction mixture to thermal aftertreatment.
IPC 1-7
IPC 8 full level
B01J 27/128 (2006.01); C07B 61/00 (2006.01); C07C 46/00 (2006.01); C07C 46/06 (2006.01); C07C 50/24 (2006.01)
CPC (source: EP US)
C07C 46/06 (2013.01 - EP US)
C-Set (source: EP US)
Designated contracting state (EPC)
CH DE FR GB LI
DOCDB simple family (publication)
DE 4405929 C1 19950309; DE 59500927 D1 19971211; EP 0669309 A1 19950830; EP 0669309 B1 19971105; IN 182416 B 19990410; JP 3754469 B2 20060315; JP H07324053 A 19951212; US 5559257 A 19960924
DOCDB simple family (application)
DE 4405929 A 19940224; DE 59500927 T 19950213; EP 95101915 A 19950213; IN 129CA1995 A 19950209; JP 3541795 A 19950223; US 39246995 A 19950222